Review Request: 7193406 - Clean-up JDK Build Warnings in java.util, java.io (original) (raw)

Stuart Marks stuart.marks at oracle.com
Fri Aug 24 01:43:35 UTC 2012

On 8/23/12 5:12 PM, Andrew Hughes wrote:

Dan Xu wrote:

Please review the fix of CR 7193406 at http://cr.openjdk.java.net/~dxu/7193406/webrev/. And it enables fatal warning flag in the following make file.

make/java/jar/Makefile Please don't do this, at least not unconditionally.

Right, we had been enabling fatal warnings in the various makefiles but we've stopped doing so since it has started to cause problems. The intent was to enable fatal warnings by default in individual makefiles, as those areas of the build were cleared of warnings. That way, the introduction of a new warning into a warnings-free area would break the build.

The problem is that because of implicit compilation, as code is modified, files can shift around being compiled by different Makefiles. Thus an apparently innocuous change might cause a file with warnings to be built by a different javac run from a makefile that has fatal warnings enabled, causing an unexpected build breakage.

Anyway, Dan, please don't enable this flag in this (or any other) Makefile. Sorry, I thought I had mentioned this to you before.

At the very least, these should not be forced on if the user has explicitly built with them set to false. If I set JAVACWARNINGSFATAL=false, I don't expect part of the build to ignore this and use -Werror, possibly then causing build failures.

Yes, it should always be possible to override this by specifying JAVAC_WARNINGS_FATAL=false on the make command line. This overriding should work if the value is specified directly in a Makefile, e.g.

 JAVAC_WARNINGS_FATAL = true

However, there are several cases where the following occurs:

 SUBDIRS_MAKEFLAGS += JAVAC_WARNINGS_FATAL=true

and this is not overridable on the command line. That's wrong. If these are causing problems for you, please do submit patches.

Although we still occasionally run into problems with implicit compilation causing unexpected build failures, I don't want to remove the fatal warnings settings wholesale. The settings in place now do seem to be keeping at least some parts of the build warning-free.

The new build system will change all of this completely, of course. I don't think they have a solution yet for applying different flags to different parts of the build.

In FilePermission.java file, I make one change to its method signature,

public Enumeration elements() ==> public Enumeration elements() It's in a package-private class so I doubt it. Even if it wasn't, a new major release is the perfect time to fix these issues.

Yes, this one is fine because it's a private class.

For warnings fixes we're trying to avoid making any API changes, since those have to go through some additional process steps.

s'marks

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